Effect of axial extension on parameterized endwall contour with incidence change for low-pressure turbine linear cascade.

Non-axisymmetric endwall (NAEW) contouring method has shown promising results to reduce secondary losses using both experimental and numerical studies. The parameterized endwall contour shaping redistributes the local static pressure resulting in a reduced effect of loss generating elements. Present study discusses the effect of the fore extension of NAEW shape on secondary flow field at design and off-design incidences numerically for low-pressure (LP) linear turbine cascade. The steady Reynolds averaged Navier-Stokes (RANS) simulations are performed using shear stress transport (SST) based γ − θ turbulence model in commercial solver. The simulations are performed for a low Re =1.6×105 based on blade chord and isentropic exit velocity. The two-part study discusses the effect of upstream extension of NAEW profile at design and off-design incidence cases, respectively. The study observed reduction in total pressure loss coefficient ( ω ¯ ) by implementing NAEW contour profiling. The NAEW with 40 % Cax extension is the most favorable case. [ABSTRACT FROM AUTHOR]